/Engine/Source/Editor/LevelEditor/Public/LevelEditorSubsystem.h
Close the current Persistent Level (without saving it). Create a new Level base on another level and save it. Load the new created level.
True if the operation succeeds.
bool NewLevelFromTemplate ( const [FString](API\Runtime\Core\Containers\FString) & AssetPath, const [FString](API\Runtime\Core\Containers\FString) & TemplateAssetPath )